Horror escape rooms are well known for their ability to keep construction costs low - the maniac's lair, the abandoned warehouse, and similar locations don't usually require excessive decorating. In fact, sometimes the awfully-looking venue can be a perfect fit for a horror game (assuming to can put together a comfortable lobby, clean restrooms, and ok-ish gamemaster room).
Reasonable choice of theme allowed Laurent to invest more on elaborated electronic props, horror equipment, and perfectly realistic props to scare the hell out of players. The overall cost of the props package will all the decoration elements was 9990$